receptive fields

receptive fields

stimulus region and features that affect the activity of a cell in a sensory system
- consists of stimulus features that excite or inhibit cells

on center bipolar cells

a retinal bipolar cell that is excited by light in the center of its receptive field
- inhibited by glutamate (due to receptors)
- functions normally in condition with no light: glutamta inhibit receptors, resulting in hyperpolarization and decreased neurotransmitter release
-special skills activated in conditions with light: inhibition by glutamate overpowered by excitiation from light resulting in depolarization and increased neurotransmitter release

off center bipolar cells

a retinal bipolar cell that is inhibited by light in the center of its receptive field
- excited by glutamate (due to receptors)

functions normally in conditions with no light
- glutamate excited receptors, resulting in depolarization and increased neurotransmitter release

special skills activated in conditions with light
- excitation by glutamate overpowered by inhibition from light resulting in hyperpolarization and decreased neurotransmitter release

on center ganglion cells

A retinal ganglion cell that is activated when light is presented to the center, rather than the periphery, of the cell's receptive field
- in conditions with light, increased firing rate
- in conditions with no light, decreased firing rate

off center ganglion cell

a retinal ganglion cell that is activated when light is presented to the periphery, rather than the center, of the cell's receptive field
- in conditions with light, decreased firing rate
- in conditions with no light, increased firing rate

neurons in the retina and LGN have ...

concentric receptive fields
- neurons in the LGN stimulated by retinal ganglion cells also have this organization

on-center/off-surround receptive field

concentric receptive fields in which stimulation at the center excites the cell of interest while stimulation of surround inhibits

off center/on surround receptive field

referring to a concentric receptive field in which stimulation at the center inhibits the cell of interest while stimulation of the surround excites it

lateral inhibition

phenomenon in which interconnected neurons inhibit their neighbors, producing contrast at the edges of regions
- can see this in bipolar cells relaying info from photoreceptors to ganglion cells
- sharpens edges